A cool technique to incorporate into your metal solos is the use of octave jumps (or leaps). By this I mean you take a lick and alternate playing it at a higher or lower octave (12 frets apart) on the same group of strings and using the same fingering. So your left hand will jump up and down the neck playing the same notes at a higher or lower pitch. I first came across this idea many years ago when I saw Yngwie Malmsteen perform the song ‘Rising Force’ on an old instructional video. I was blown away! Not only did it sound great, but visually it looked very impressive. That’s not to say this technique is all just for show though. While you could technically change octaves by switching strings and staying in a closer position, you get a much more fluid and smoother sound when you use the same strings/shapes and employ 12 fret position shifts.

To illustrate this concept, I’ve come up with two long licks. Both examples are in A minor and use a Vm-IV-VI-V-Im chord progression. For you theory buffs out there, the Vm (Em), VI (F) and Im (Am) chords are diatonic to A Natural minor/Aeolian. The major IV chord (D) is taken from A Dorian, and the major V chord (E) is taken from A Harmonic minor.

EXERCISE 1

Although this technique can be done using any sort of lick, it works great when used with arpeggios over chord progressions. Exercise 1 takes two-string arpeggios outlining the chords, but for each chord we alternate by playing the arpeggio high up the neck and then playing the same thing an octave lower. Each arpeggio is played using a sixteenth note triplet followed by an eighth note. That eighth note will help you because rather than hold it for the absolute full length, you can start moving down (or up) the octave a fraction of a second before the note is due to end. This gives you a bit of extra time to make the leap.
Some other pointers to help you with this technique are:

Practice the arpeggio sequence in the high or low position separately first and without the jumps.

Practice the jumps using only the one finger you start each arpeggio on (which should be your fourth or third finger).

Once you can do this, add in the next note with your first finger, then the next, and so on.

Use the same fingerings when you jump down/up to the same shape.

Slightly before finishing one arpeggio, turn your gaze to the fret you have to get to for the next one. That way you can see where you need to go ahead of time.

While using the same chords and basic arpeggio shapes, this lick is much harder than Exercise 1 since it features a steady stream of sixteenth notes across three strings. Thus, there is no long note at the end of each arpeggio to leave early. You’ve just got to go for it and move to each shape as fast and accurately as possible. The best way to work on this is to start really, really slow. Try 60bpm and gradually build it up (on the cover CD I’ve recorded both licks at 140bpm). The more you practice, the more these jumps will get programmed into the muscle memory of your left hand.